Berberine: effects on blood sugar, cholesterol and weight

In studies, berberine has lowered blood sugar and certain blood fats. The average effects are mostly moderate, study quality varies, and the evidence for meaningful weight loss is much less convincing. If you already take medication, you should not simply add berberine on top, because of possible interactions. It is not a substitute for prescribed treatment for diabetes or obesity.

What is berberine?

Berberine is an isoquinoline alkaloid found in plants, barberry among them. Research has focused mainly on its effects on glucose, insulin, blood lipids and liver metabolism. It is a biologically active substance; the fact that it comes from a plant says nothing about how well it is tolerated or how it should be used. Clinical review

When taken by mouth, only a small amount of unchanged berberine reaches the circulation. Pharmacokinetic reviews put its bioavailability below 1 percent and report that 11 to 23 percent is excreted in the stool. These figures come from different study conditions and are not a fixed value for every product or every person. The poor absorption explains part of the interest in modified formulations. Pharmacokinetic review

In the United States, dietary supplements of this kind are not approved by the FDA for efficacy and safety before sale, the way drugs are. This US rule says nothing about whether a particular product may be sold in Germany. For medical treatment, what matters is whether a product has been tested and approved for the specific purpose. FDA on dietary supplements

Which plants does berberine come from?

Berberine occurs in the roots, rhizomes and bark of various plants. Sources that are used include:

• Barberry (Berberis vulgaris)
• Goldenseal, also called Canadian yellowroot (Hydrastis canadensis)
• Oregon grape (Mahonia aquifolium)
• Indian barberry (Berberis aristata)

A plant extract is not the same thing as isolated berberine. It contains other substances, and absorption can differ. The NCCIH (the US National Center for Complementary and Integrative Health) stresses this limitation especially for goldenseal: results from berberine studies cannot automatically be applied to goldenseal products. NCCIH: Goldenseal

How does berberine work in the body?

Berberine appears to act on metabolic regulation at several points. In studies of type 2 diabetes, blood sugar, insulin resistance and blood lipids sometimes shift together. That suggests several processes are involved, but it does not yet prove any single mechanism of action. Meta-analysis on metabolic markers

The gut could be an important point of action. In the PREMOTE study, 409 people with newly diagnosed type 2 diabetes at 20 centers were assigned to different treatments. The groups that received berberine showed changes in HbA1c and in the microbiome, including in bile acid metabolism. This offers clues to how a poorly absorbed substance might still have effects elsewhere in the body. PREMOTE study

Formulations with better absorption need to be considered separately. A crossover pilot study in five healthy men found higher blood exposure to berberine with dihydroberberine: the area under the concentration curve over 120 minutes was 284.4 versus 42.3 ng/ml × 120 min, compared with 500 mg of berberine. The higher figure referred to the 100 mg dihydroberberine condition that was tested. No differences in glucose or insulin were found in this short trial. An absorption advantage is therefore not yet a proven treatment advantage. Pilot study on absorption

What role does AMPK play?

AMPK is an enzyme complex that senses a cell’s energy status and adjusts metabolic pathways to match. It is often cited as the explanation for berberine’s effects. Much of the evidence for this comes from lab and animal experiments.

Clinical studies usually measure outcomes such as fasting insulin or HOMA-IR, a calculated estimate of insulin resistance. Lower values can fit with improved insulin action, but they do not directly show which signaling pathway was responsible. Meta-analysis on insulin and glucose

Which benefits are supported by studies?

An overarching review assessed eleven meta-analyses of randomized trials. It found signs of changes in glucose, insulin resistance, blood lipids, body measurements and inflammatory markers. At the same time, it criticized the methodological quality. Small studies, varying comparison groups and poorly described blinding limit how confident the conclusions can be. Umbrella review, Review on blood lipids

Blood sugar and insulin resistance

A meta-analysis of 37 randomized trials with 3,048 people with type 2 diabetes reported an average HbA1c reduction of 0.63 percentage points. The 95 percent confidence interval ran from −0.72 to −0.53 percentage points. Fasting plasma glucose fell by 0.82 mmol/l, and the value two hours after a meal by 1.16 mmol/l. Higher starting values went along with larger changes. Xie and colleagues, 2022

Another analysis was limited to 20 placebo-controlled trials with 1,761 people. Here the mean differences were −0.52 mmol/l for fasting glucose, −2.36 mU/l for fasting insulin and −0.85 HOMA-IR units. These results do not come from the same selection of studies as the previous figures. Zhao and colleagues, 2023

In the first analysis, reported adverse events did not increase overall; the pooled relative risk was 0.73. No increase in low blood sugar (hypoglycemia) was found either. Short studies with limited numbers of participants, however, cannot rule out rare risks or problems with drug combinations.

Cholesterol and cardiovascular markers

In 18 placebo-controlled trials with 1,788 participants, most used 900 to 1,500 mg of berberine per day for 4 to 24 weeks. On average, LDL cholesterol fell by 0.46 mmol/l, roughly 18 mg/dl. Total cholesterol dropped by 0.48 mmol/l and triglycerides by 0.34 mmol/l, roughly 30 mg/dl. HDL rose slightly, by 0.06 mmol/l. Blais and colleagues, 2023

An earlier analysis of 16 trials with 2,147 participants found similar changes in total cholesterol, LDL and triglycerides. A 2025 analysis, by contrast, found no statistically significant effects on HDL or on systolic or diastolic blood pressure. Different study selections can explain discrepancies like these. Ju and colleagues, 2018, Liu and colleagues, 2025

Better lab values also do not mean that fewer heart attacks or strokes have been demonstrated. Prescribed lipid-lowering treatment should therefore not be replaced with berberine.

Weight and body composition

A dose-response meta-analysis of ten trials found no statistically significant change in body weight: the mean difference was −0.11 kg, with a 95 percent confidence interval of −0.99 to +0.76 kg. At the same time, BMI and waist circumference fell on average by 0.29 kg/m² and 2.75 cm, respectively. Xiong and colleagues, 2020

The 2025 analysis reported −3.27 cm in waist circumference and −0.435 kg/m² in BMI. These are results from different datasets, not a personal forecast of losing 2.75 to 3.27 cm around the waist. Above all, they do not justify expecting substantial weight loss. Liu and colleagues, 2025

Fatty liver and MASLD

In metabolic fatty liver disease, now often called MASLD and referred to as NAFLD in older studies, liver values have also been studied. A meta-analysis of ten trials with 811 patients reported standardized mean differences of −0.72 for ALT, −0.79 for AST and −0.62 for GGT; for HOMA-IR the value was −1.56. Standardized differences are not absolute changes in U/l and cannot be read directly as an expected personal lab result. Nie and colleagues, 2024

An 18-week phase 2 trial of berberine ursodeoxycholate needs to be considered separately. This experimental salt combines berberine with ursodeoxycholic acid. At 1,000 mg twice daily, liver fat fraction measured by MRI fell by an absolute 4.8 percentage points, compared with 2.0 on placebo. The result applies to this investigational product and not to any berberine capsule. Harrison and colleagues, 2021

PCOS and hormonal metabolism

In polycystic ovary syndrome with insulin resistance, the evidence is uncertain. A meta-analysis of nine trials found no clear differences between berberine and metformin in insulin resistance, glucose and lipid metabolism, or reproductive hormone levels. An added benefit of berberine together with metformin over metformin alone was not established either. Li and colleagues, 2018

“No significant difference” does not mean here that the two treatments have been proven equivalent. The authors considered the data insufficient. A possible effect on insulin resistance also does not translate into a proven benefit for fertility or pregnancy.

Gut microbiome

The PREMOTE study compared berberine, probiotics plus berberine, probiotics alone and placebo over twelve weeks. Changes in HbA1c and the microbiome occurred together in the groups that received berberine. Which bacterial changes are actually causal and beneficial in the long run remains an open question. PREMOTE

The umbrella review also included findings on Helicobacter pylori and colorectal adenomas. Narrowly focused studies like these do not justify general use for a “gut cleanse” or for treating an infection yourself. Review

Is berberine comparable to Ozempic or other GLP-1 drugs?

Berberine and semaglutide are different substances with different mechanisms of action and different bodies of evidence. Calling berberine “natural Ozempic” is therefore misleading.

In a large obesity trial, once-weekly semaglutide at a dose of 2.4 mg over 68 weeks led to an average weight change of −14.9 percent, compared with −2.4 percent on placebo. The berberine meta-analysis mentioned above, by contrast, showed no established effect on weight. This is not a direct comparison within the same trial; moreover, the 2.4 mg study describes obesity treatment and not every use of a semaglutide product. STEP 1 trial

Berberine and metformin compared

A small pilot study compared berberine and metformin, each at 0.5 g three times daily, over three months in 36 adults with newly diagnosed type 2 diabetes. In the berberine group, HbA1c fell from 9.5 to 7.5 percent. In a further part of the study, 48 people with inadequate glucose control received berberine as an add-on: HbA1c fell from 8.1 to 7.3 percent, fasting insulin by 28.1 percent and HOMA-IR by 44.7 percent. Temporary gastrointestinal complaints were reported in 34.5 percent. These small, short studies do not demonstrate long-term equivalence with metformin. Yin and colleagues, 2008

Feature	Berberine	Metformin	GLP-1 treatment, using semaglutide as the example
Use in the studies cited	Oral, daily amount split into doses	Oral, 0.5 g three times daily in the pilot trial	Weekly injection under the skin in the trial cited
Status	Dietary supplements are not an approved replacement therapy	Prescription drug	Prescription drug
HbA1c result	Average −0.63 percentage points across 37 trials	Similar effect in a three-month pilot comparison	The comparison here uses a weight trial, not an HbA1c trial
Weight	No established change in one meta-analysis	Not quantified in the pilot comparison cited	−14.9 percent over 68 weeks vs. −2.4 percent on placebo
Strength of evidence	Many small, heterogeneous studies	Broad clinical experience; direct comparison with berberine is small	Large randomized trial in overweight or obesity

The table compares different studies and is not a ranking of interchangeable treatments. For combinations, interactions also matter: in healthy adults, goldenseal extract reduced metformin exposure by about 25 percent. That is a finding about the plant extract, not the same as a study of taking pure berberine. NCCIH on the interaction

Which amounts and timings have been studied?

In many studies, daily amounts were 900 to 1,500 mg over 4 to 24 weeks. The pilot comparison with metformin used 0.5 g three times daily. These figures describe research protocols and do not add up to a generally recommended self-medication dose. Lipid meta-analysis, Pilot study

The protocols differ in several respects, including:

• The daily amount is often split into two or three doses.
• Some studies tie intake to meals, partly because of gastrointestinal tolerability.
• Amounts were sometimes adjusted when side effects occurred; no general titration schedule can be derived from this.
• Changes were measured over weeks, not after individual capsules.

Whether taking it is reasonable at all depends especially on existing conditions and other medications.

What side effects can berberine have?

The most commonly reported are constipation, diarrhea, abdominal pain and other gastrointestinal complaints. In the placebo-controlled lipid trials, such events occurred in 2 to 23 percent of people on berberine and 2 to 15 percent on placebo. No serious adverse events were reported there; even so, the limited study duration does not allow any comprehensive statement about long-term safety. Blais and colleagues

The 34.5 percent rate of temporary gastrointestinal complaints in the small diabetes study shows that tolerability can vary from one study to another. The experimental berberine ursodeoxycholate also mainly caused diarrhea and abdominal discomfort; its side-effect data should not be applied to ordinary berberine without scrutiny. Diabetes study, Phase 2 trial

Yellowing of the skin or eyes, severe symptoms or signs of low blood sugar should be checked by a doctor promptly. If new symptoms appear after starting a product, its name, its ingredients and every medication taken alongside it are important information.

Who should avoid berberine, and which interactions matter?

Berberine should be avoided during pregnancy and breastfeeding and in infants. One concern is that it can displace bilirubin from its binding to albumin. An older lab and animal study found that berberine displaced bilirubin about ten times more strongly than phenylbutazone. That is not a measured risk figure for pregnant people, but it explains part of the special caution with newborns. Bilirubin study

Before combining it with medicines, a check by a doctor or pharmacist is required. Interaction areas that have been described include ciclosporin A, digoxin and glucose regulation. For metformin, the goldenseal finding explained above should be kept distinct. Pharmacokinetic review

In studies, berberine affects various CYP enzymes, including CYP3A4/5, CYP2D6, CYP2C9, CYP2E1, CYP1A1/2 and several CYP2B forms. How much this matters depends on the product, the dose and the drug. Possible changes are especially relevant for drugs with a narrow therapeutic range, where even small shifts in concentration can become dangerous. Review of CYP interactions

How can you judge the quality of a product?

A product label should clearly state the exact substance, the amount per serving, other ingredients and the manufacturer’s details. Independent testing can make identity and purity easier to verify, but it does not prove any medical benefit.

Four questions help in assessing a product:

• Does the milligram figure refer to berberine itself or to a plant extract?
• Is it berberine HCl, dihydroberberine or another formulation?
• Does it contain additional active ingredients that may have their own interactions?
• What did any stated external test actually examine?

Higher absorption is not automatically a quality advantage for treatment. Nor can an amount used in a study simply be transferred to a product with a different composition. Undeclared ingredients have been found in some goldenseal products, which underlines the importance of a traceable composition. NCCIH

Which blood values can show changes?

If berberine is taken under medical supervision, the specific question and the appropriate follow-up tests should be settled beforehand. HbA1c, fasting glucose and blood lipids answer different questions. Liver enzymes alone measure neither liver fat content nor overall liver health.

Measure	What it describes	Average changes in the studies cited
HbA1c	Blood sugar exposure over roughly the past three months	−0.63 percentage points
Fasting glucose	Glucose level in the fasting state	−0.82 mmol/l in a diabetes meta-analysis
Fasting insulin and HOMA-IR	Indirect information about insulin regulation	−2.36 mU/l and −0.85, respectively, in placebo-controlled trials
LDL and triglycerides	Components of the blood lipid profile	−0.46 and −0.34 mmol/l, respectively
ALT and AST	Enzymes that can rise with liver damage, among other things	Changes as standardized mean differences, not as a fixed drop in U/l

The table values come from the linked glucose, insulin, lipid and liver meta-analyses. They are group averages. Diet, weight, medications and illnesses can change the same values; a better follow-up result therefore does not on its own prove that berberine was the cause.

Frequently asked questions

Is berberine really “natural Ozempic”?

No. It works differently and has no comparable evidence for substantial weight loss. In the semaglutide trial cited, the average weight change over 68 weeks was −14.9 percent; in the berberine meta-analysis it was −0.11 kg, with no statistically significant effect. Different studies and units should not be read as a direct head-to-head comparison.

How much can berberine lower blood sugar?

In type 2 diabetes, one meta-analysis found average reductions of 0.63 percentage points in HbA1c, 0.82 mmol/l in fasting glucose and 1.16 mmol/l in glucose two hours after a meal. In another analysis, fasting insulin fell by 2.36 mU/l and HOMA-IR by 0.85. Your personal effect cannot be predicted from these figures.

How much berberine should you take per day?

No general recommendation can be derived from the studies. Amounts studied most often were 900 to 1,500 mg per day, split into several doses. Whether a product is suitable in an individual case has to be clarified, above all because of interactions.

Which side effects are common?

Mainly diarrhea, constipation and abdominal discomfort. Their frequency varied considerably between studies. New or worsening symptoms should prompt a review of the product and of possible interactions.

Does berberine work as well as metformin?

A small, three-month pilot study found similar effects on blood sugar. That is not enough to demonstrate equivalence, long-term safety or the same protection against complications. Metformin must therefore not be replaced on your own on this basis.

Who should not take berberine?

Pregnant and breastfeeding people and infants should avoid it. Anyone taking medicines needs a specific interaction check before starting it. A plant origin does not protect against changes in drug levels.

Does berberine lead to weight loss?

These results do not allow any promise of meaningful weight loss. Some analyses show smaller changes in BMI or waist circumference, while the effect on weight is unclear. These measures are not interchangeable.

Is dihydroberberine better than ordinary berberine?

In a very small study, it was better absorbed. A better effect on glucose or insulin was not shown there. Larger and longer studies would be needed to establish clinical superiority; the same principle applies to phytosome formulations.

Sources

• Khoshandam A, Imenshahidi M, Hosseinzadeh H. Pharmacokinetic of berberine, the main constituent of Berberis vulgaris L.: a comprehensive review. Phytother Res. 2022;36(11):4063-4079. doi:10.1002/ptr.7589 Source link
• U.S. Food and Drug Administration. Questions and answers on dietary supplements. Accessed July 24, 2026. Source link
• Imenshahidi M, Hosseinzadeh H. Berberine and barberry (Berberis vulgaris): a clinical review. Phytother Res. 2019;33(3):504-523. doi:10.1002/ptr.6252 Source link
• National Center for Complementary and Integrative Health. Goldenseal: usefulness and safety. National Institutes of Health. Accessed July 24, 2026. Source link
• Guo J, Chen H, Zhang X, et al. The effect of berberine on metabolic profiles in type 2 diabetic patients: a systematic review and meta-analysis of randomized controlled trials. Oxid Med Cell Longev. 2021;2021:2074610. doi:10.1155/2021/2074610 Source link
• Zhang Y, Gu Y, Ren H, et al. Gut microbiome-related effects of berberine and probiotics on type 2 diabetes (the PREMOTE study). Nat Commun. 2020;11(1):5015. doi:10.1038/s41467-020-18414-8 Source link
• Moon JM, Ratliff KM, Hagele AM, Stecker RA, Mumford PW, Kerksick CM. Absorption kinetics of berberine and dihydroberberine and their impact on glycemia: a randomized, controlled, crossover pilot trial. Nutrients. 2021;14(1):124. doi:10.3390/nu14010124 Source link
• Zhao JV, Huang X, Zhang J, Chan YH, Tse HF, Blais JE. Overall and sex-specific effect of berberine on glycemic and insulin-related traits: a systematic review and meta-analysis of randomized controlled trials. J Nutr. 2023;153(10):2939-2950. doi:10.1016/j.tjnut.2023.08.016 Source link
• Li Z, Wang Y, Xu Q, et al. Berberine and health outcomes: an umbrella review. Phytother Res. 2023;37(5):2051-2066. doi:10.1002/ptr.7806 Source link
• Ju J, Li J, Lin Q, Xu H. Efficacy and safety of berberine for dyslipidaemias: a systematic review and meta-analysis of randomized clinical trials. Phytomedicine. 2018;50:25-34. doi:10.1016/j.phymed.2018.09.212 Source link
• Xie W, Su F, Wang G, et al. Glucose-lowering effect of berberine on type 2 diabetes: a systematic review and meta-analysis. Front Pharmacol. 2022;13:1015045. doi:10.3389/fphar.2022.1015045 Source link
• Blais JE, Huang X, Zhao JV. Overall and sex-specific effect of berberine for the treatment of dyslipidemia in adults: a systematic review and meta-analysis of randomized placebo-controlled trials. Drugs. 2023;83(5):403-427. doi:10.1007/s40265-023-01841-4 Source link
• Liu D, Zhao H, Zhang Y, Hu J, Xu H. Efficacy and safety of berberine on the components of metabolic syndrome: a systematic review and meta-analysis of randomized placebo-controlled trials. Front Pharmacol. 2025;16:1572197. doi:10.3389/fphar.2025.1572197 Source link
• Xiong P, Niu L, Talaei S, et al. The effect of berberine supplementation on obesity indices: a dose-response meta-analysis and systematic review of randomized controlled trials. Complement Ther Clin Pract. 2020;39:101113. doi:10.1016/j.ctcp.2020.101113 Source link
• Nie Q, Li M, Huang C, et al. The clinical efficacy and safety of berberine in the treatment of non-alcoholic fatty liver disease: a meta-analysis and systematic review. J Transl Med. 2024;22(1):225. doi:10.1186/s12967-024-05011-2 Source link
• Harrison SA, Gunn N, Neff GW, et al. A phase 2, proof of concept, randomised controlled trial of berberine ursodeoxycholate in patients with presumed non-alcoholic steatohepatitis and type 2 diabetes. Nat Commun. 2021;12(1):5503. doi:10.1038/s41467-021-25701-5 Source link
• Li MF, Zhou XM, Li XL. The effect of berberine on polycystic ovary syndrome patients with insulin resistance (PCOS-IR): a meta-analysis and systematic review. Evid Based Complement Alternat Med. 2018;2018:2532935. doi:10.1155/2018/2532935 Source link
• Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002. doi:10.1056/NEJMoa2032183 Source link
• Yin J, Xing H, Ye J. Efficacy of berberine in patients with type 2 diabetes mellitus. Metabolism. 2008;57(5):712-717. doi:10.1016/j.metabol.2008.01.013 Source link
• Chan E. Displacement of bilirubin from albumin by berberine. Biol Neonate. 1993;63(4):201-208. doi:10.1159/000243932 Source link
• Bathaei P, Imenshahidi M, Hosseinzadeh H. Effects of Berberis vulgaris, and its active constituent berberine on cytochrome P450: a review. Naunyn Schmiedebergs Arch Pharmacol. 2025;398(1):179-202. doi:10.1007/s00210-024-03326-x Source link